JP2002060074A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeder having separate rollers and retard rollers opposed to the separate rollers and allowing easy replacement of the retard rollers. SOLUTION: This paper feeder comprises a curved transfer route connecting a paper feed tray 51 to a paper delivery tray 52 and having a pair of openable sheet transfer guides separate rollers 12 supported on an upper frame 2, and detachable retard rollers 13 partly projected to the transfer route side in one sheet transfer guide and disposed so as to elastically come in contact with the separate rollers 12. The retard rollers 13 can be replaced by removing a part 60 of the transfer guide with the upper frame 2 opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for conveying sheet-like conveyance media, such as sheets, which are stacked and accommodated in a tray, one by one and conveying the medium to a downstream side.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as a copying machine, a facsimile machine, a printer, etc., stacked sheets are separated one by one and are conveyed to a processing section by a conveying roller device provided in a conveying path. Means are provided.

Conventionally, for example, in order to send out the paper from the paper feed tray, a pickup roller is disposed on the paper feed tray, and the paper taken out by the pickup roller is separated by a paper separating apparatus including a separate roller and a retard roller. It is configured to be separated into individual sheets and sent out to a processing unit such as a reading unit or a recording unit.

In the case where the paper feeder is an automatic document feeder for reading a document (hereinafter, referred to as “ADF”) disposed above an image forming apparatus in combination with a flatbed scanner (hereinafter, referred to as “FBS”), A mechanism is adopted in which the paper transport path is formed in a substantially U-shape in the horizontal direction, and the paper is fed while being curved with a very small radius.

More specifically, as shown in FIG. 6, a retard roller 13 is supported by a support link mechanism 70 on both sides in a direction perpendicular to the sheet conveying direction of the sheet separating apparatus 11. The support link mechanism 70 includes a horizontal link member 7 that swings about the shaft 15a of the drive roller 15 of the transport roller device.
1 and a vertical link member 72 supporting the retard roller 13
It is composed of

The shaft 13a of the retard roller 13 is connected to a reverse U formed on the lower surface of a paper guide 60 forming a paper transport path.
The retard roller 13 is supported so as to be slidable up and down in the shaft support portion 61 of the U-shaped groove, and the axis of the retard roller 13, the axis of the separate roller 12, and the contact point of both rollers 12, 13 are always in a straight line Is guided by the shaft support 61. Further, the separate roller 12 and the retard roller 13
Are set so that a predetermined value of nip pressure is generated between the two rollers.

[0007] A pressing force adjusting member 30 is provided as means for causing the retard roller 13 to resiliently contact the separate roller 12, so that the nip pressure of the retard roller 13 with respect to the separate roller 12 can be appropriately adjusted, and the weight of the paper to be fed is reduced. Sending does not occur.

The pressing force adjusting member 30 includes an adjusting bolt 3
4 and a compression spring 32. The bolt 34 is screwed on the horizontal link member 71, and the compression spring 32 is elastically mounted between the head of the bolt 34 and the intermediate frame. Thereby, the horizontal link member 71 and the vertical link 72
Is urged upward. Further, the amount of compression of the compression spring 32 is changed by the loosening operation of the bolt 34, and the urging force is adjusted. The shaft 13a of the retard roller is guided by the shaft supporting portion 61 of the paper guide 60, and the pressing action of the retard roller 13 on the separate roller 12 is performed in a direction coinciding with a line connecting the axis of both rollers.

[0009]

In such a paper feeder, if the retard roller is damaged or worn and the separating performance of the paper is reduced, it is necessary to replace the retard roller. However, in the conventional paper feeding device, the paper guide forming the paper conveyance path is fixed to the paper feeding device, and the retard roller is assembled to the paper feeding device. Therefore, in order to replace the retard roller, it is necessary to remove a drive transmission gear, other rollers, a link mechanism, and the like around the retard roller, and when replacing the retard roller or performing maintenance around the retard roller. ,
The entire paper feeder had to be disassembled. In this way, the replacement of the retard roller is a major task,
In a short period of time, maintenance could not be performed by a serviceman, and the retard roller could not be replaced without returning to the service center.

Further, since the elastic pressing member acts on the retard roller from directly below, the load of the retard roller is applied to the elastic pressing member, and the pressing force must be large. And the paper feeder itself became bulky.

The present invention is intended to solve the problem of the conventional paper feeder. In particular, a serviceman can easily replace a retard roller for separating sheets one by one in a field, and the compact paper feeder is compact. It is intended to provide.

[0012]

The present invention comprises a pair of paper transport guides, a curved transport path connecting a paper feed tray and a paper discharge tray, and a paper feed supported by an openable upper frame. The present invention relates to a sheet feeding device including a member, and a detachable detachable member that partially protrudes into the one sheet conveyance guide toward the conveyance path and is arranged to elastically contact the sheet feeding member.

According to a first aspect of the present invention, the separation member can be replaced by opening the upper frame and removing a part of the one sheet transport guide. Therefore, replacement of the separation member can be easily performed.

According to a second aspect of the present invention, the separation member is integrally supported by the support bracket, and is detachably and rotatably attached to one end of an arm member swingably provided in the transport guide. It is characterized by having. Therefore, the separation member supported by the support bracket swings in an arc shape via the arm member.

According to a third aspect of the present invention, there is provided a sheet feeding member which is connected to a sheet feeding tray and a sheet discharging tray and is provided with a pair of sheet conveying guides, a curved conveying path, a sheet feeding member supported by an openable and closable upper frame, and A detachable separation member partially protruding toward the conveyance path inside one of the paper conveyance guides and disposed so as to elastically contact the paper feeding member;

An arm member is swingably mounted in the paper transport guide. Therefore, the separating member swings via the arm member and elastically contacts the sheet feeding member.

According to a fourth aspect of the present invention, the support bracket includes:
The arm member, the elastic pressing member, and the separating member are provided in an openable and closable intermediate frame surrounded by a transport guide, and the intermediate frame is further provided with a paper transport driving roller. Therefore, the space inside the curved conveyance path is effectively used, and a compact configuration can be achieved.

According to a fifth aspect of the present invention, there is provided a separate roller for conveying a sheet to an image processing section, wherein the separating member is a retard roller which rotates in a direction opposite to the sheet conveying direction and separates the sheets one by one. Features. Therefore, when a plurality of sheets enter between the separate roller and the retard roller, the retard roller rotates in the reverse direction, whereby the lowermost sheet is pushed back, and the separated sheet is conveyed downstream by the separate roller.

According to a sixth aspect of the present invention, the inner surface of the upper frame forms a part of the other of the pair of transport guides, and the frame further includes a pickup roller and a paper transport driven roller. When opened, a part of the paper transport path is opened, and the intermediate frame can swing up and down. Therefore, in a state where the upper frame is opened, the intermediate frame can be further opened, so that almost all of the curved conveyance path is opened.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A paper feeder according to one embodiment of the present invention will be described with reference to the illustrated example. The ADF 1 shown in FIG. 1 is used in combination with a facsimile machine or an image forming apparatus and is used for reading an image of a document. In the ADF 1, the document is transported through a curved transport path 6 configured in a laterally U-shape in a side view, and a scanning device 43 (located below a platen 7 disposed below the transport path 6). 5 (see FIG. 5).

An upper frame 2 and an intermediate frame 3 are swingably arranged with respect to a base frame 4 arranged above the image forming apparatus. The upper frame 2 is provided to be swingable about a support shaft 2 a formed on the base frame 4. In the example shown in FIG.
The upper frame 2 is provided with a pickup roller 10 for taking in a document from a paper feed tray 51, a separate roller 12 of a paper separating device 11, a press roller 16 of a transport roller device 14, and a curved transport path 6. A press roller 18 is attached to the large-diameter drive roller 17.

The upper surface guide member 60 (see FIG. 2) is provided on the intermediate frame 3 according to the direction in which the sheet is transported.
And the retard roller 13 of the sheet separating device 11 that partially protrudes from the upper surface guide member 60, and the transport roller device 14
The drive roller 15 and the drive roller 8a of the discharge roller device 8 are attached, and a paper guide 21 (see FIG. 2) connected to the discharge tray 52 is provided. The base frame 4 is provided with a large-diameter drive roller 17 and a driven roller 8b on the discharge side for transporting a sheet at a curved portion of the transport path 6, and the base frame 4 has a reading unit and a discharge side. The guide member of the transport path 16 is disposed.

In the ADF 1 constructed by combining the above-described frames, in order to convey the paper along the conveyance path 6, the pickup roller 10 which can be vertically oscillated is disposed in correspondence with the paper feed tray 51. The sheet is taken in and sent toward the conveyance path 6, and then only one sheet is separated between the separation roller 12 and the retard roller 13 of the sheet separation device 11, and the conveyance roller device 14 is separated.
And send it to. The transport roller device 14
Is nipped between the large-diameter drive roller 17 and the press roller 18 at the curved portion of the transport path 6,
The sheet passes through the reading section of the platen 7 and is discharged onto the sheet discharge tray 52 by the discharge roller device 8 in which the drive roller 8a and the press roller 8b face each other.

A pressing force adjusting mechanism 30 is provided for the retard roller 13 of the sheet separating apparatus 11 to adjust the nip pressure between the retard roller 13 and the separate roller 12. The pressing force adjusting mechanism 30 can appropriately adjust the nip pressure of both rollers so that the sheet separating device 11 separates sheets one by one.

FIG. 2 shows the structure of the intermediate frame 3 arranged in the ADF 1. The intermediate frame 3 is provided with an upper surface guide member 60 connected to the paper feed tray 51 on the upper surface and also serving as a paper transport guide, and provided with a lower guide plate 21 for transporting the paper ejected downward. A plurality of ribs 9 for guiding the sheet to the rollers 17 are provided in the document width direction so as to protrude from the leading end of the intermediate frame 3 (see FIG. 3). The intermediate frame 3 has a retard roller 13 and a transport roller device 1.
4 and the drive roller 8 of the discharge roller device 8
The intermediate frame 3 is configured to be swingable up and down with the shaft 15a of the drive roller 15 as a fulcrum.

In the sheet separating apparatus 11, a pressing force adjusting mechanism 30 is provided so that a nip pressure of the retard roller 13 with respect to the separate roller 12 can be set. The retard roller 13 is unitized by a support bracket 24, and is held by a connection shaft 25 of an arm member 26. Further, the arm member 26 includes a gear supporting member 27.
Are connected via a fulcrum 28. The pressing force adjusting mechanism 30 is provided on the gear support member 27 side, and the compression spring 32 of the pressing force adjusting mechanism 30 is provided so that the pressing force can be adjusted by the adjusting screw 34.

At this time, the compression spring 32 and the fulcrum 28
If the distance between them is made larger than the distance between the connection shaft 25 and the fulcrum 28, the compression spring 32 will be used in accordance with the principle of leverage when the compression spring 32 acts directly on the retard roller 13 as in the above-described conventional example. In comparison, a small pressing force, that is, a small compression spring 32 is sufficient. As a result, the thickness of the intermediate frame 3 can be reduced, and the degree of freedom in arranging the compression springs 32 increases. Although the compression spring 32 is given as a preferred example of the elastic pressing member, it is needless to say that an elastic body, a damper member or the like that can produce the same effect may be used.

Next, the operation of attaching and detaching the retard roller 13 disposed on the intermediate frame 30 will be described with reference to FIG. When the upper surface guide member 60 (see FIG. 4), which is a part of the paper transport guide, is removed, a unit of the retard roller 13 and the support bracket 24 is exposed. In a state where the upper surface guide member 60 is attached,
The shaft 13a of the retard roller is arranged such that the bearing members 35 provided at both ends thereof slide within the shaft support 61 of the inverted U-shaped groove formed in the upper surface guide member 60. The shaft support 61 is formed in a deep vertical groove shape so as to allow vertical movement of the shaft 13a, so that the axis of the shaft 13a guided by the groove and the axis of the separate roller 12 are aligned. Is formed. Therefore, the retard roller 13 is arranged such that both the rollers 1
Since the nip positions of the shaft cores 2 and 13 are on a straight line, the paper does not bite into the retard roller 13 and the paper can be transported smoothly. The shaft 13 of the retard roller 13
Needless to say, the shaft supporting portion 61 for guiding a may be provided on the intermediate frame 3 side.

The replacement of the retard roller 13 will be described. First, as shown in FIG. 2, when the upper surface guide member 60, which is the upper cover of the intermediate frame 30, is removed, a unitized unit of the retard roller 13 and the support bracket 24 supported by the arm member 26 is exposed. When the upper frame 2 is closed, the retard roller 13 is regulated downward by the separate roller 12 in the function state of the sheet separating device 11. However, when the upper frame 2 is opened, the regulation of the separate roller 12 is released. Further, when the upper guide member 60 is removed and the regulation of the shaft support 61 of the inverted U-shaped groove is released, the arm member 26 and the retard roller 13 swing in an arc around the fulcrum 28 as shown in FIG. Move. As a result, the unit obtained by uniting the support bracket 24 with the retard roller 13 is lifted upward by the arm member 26, and is easy to take. Then, in order to replace the retard roller 13, the handle portion of the support bracket 24 is manually lifted, and is detached from the connection shaft 25 provided on the arm member 26.

The connecting shaft 25 is rectangular in cross section and D-cut on the short side, has a desired angle, and does not come off when the retard roller 13 is pressed against the separate roller 12. .

The width on the short side of the connection shaft 25 is set to be substantially the same as the width of the opening 69 provided in the bearing. And
When replacing the retard roller 13, the support bracket 2
The retard roller 13 can be easily removed by pivoting the shaft 4 slightly up and aligning the short side of the connection shaft 25 with the opening of the bearing 69 of the support bracket 24.

Next, the pressing force adjusting mechanism 30 will be described. The pressing adjustment mechanism 30 includes a lower surface of the paper transport path on the upper surface side of the intermediate frame 3 main body and a head flange 29 of the adjustment screw 34.
, An urging arm 33 screwed to the adjusting screw 34 and attached to the gear support member 27, the head flange 29 and the urging arm 3.
3 and a compression spring 32 interposed therebetween.
A stopper (not shown) such as a screwdriver is inserted into the adjustment screw 34 from the adjustment hole 31 (see FIG. 3), and the screw 34 is rotated by the stopper so that the head flange 29 of the screw 34 and the urging arm 33 are rotated. And change the distance. Thereby, the length of the compression spring 32 is changed between the head flange 29 of the screw 34 and the lower surface of the paper transport path, and the compression spring 32
Adjust the pressing force of. Thus, the force (nip pressure) at which the retard roller 13 supported by the support bracket 24 elastically contacts the separate roller 12 is adjusted.

Since the pressing force of the pressing force adjusting mechanism 30 is adjusted by inserting a stopper such as a screwdriver from the adjusting hole 31 of the intermediate frame 3, a small hole is formed in a part of the paper transport path of the frame 3. This is convenient because there is no hindrance to the sheet guiding action and the pressing force can be easily adjusted when the upper frame 1 is opened.

FIG. 3 is a plan view showing a state where the upper guide member 60 has been removed from the intermediate frame 3. A plurality of ribs 9 are provided on the downstream side in the sheet transport direction. A plurality of transport drive rollers 15 are provided between the ribs 9. The intermediate frame 3 has a recess.
The retard roller 13, the support bracket 24,
The arm member 26 and the gear support member 27 are housed.

Bearings are provided at both ends of the shaft 13a of the retard roller 13 via E-rings.
The upper surface guide member 60 is attached, the upper frame 2 is closed, and the upper surface guide member 60 is attached (see FIG. 1).
In, this bearing slides on the U-shaped groove 61 shown by the imaginary line. Therefore, the retard roller 13 attached to the arm member 26 that swings in an arc around the fulcrum 28 is adjusted so that the roller axis, the axis of the separate roller 12, and the nip position of both rollers are aligned. You can move.

An idler gear group 22 is provided on the gear support member 27 so that the retard roller 13 rotates in the reverse direction. The idler gear group 22 includes a driving source (not shown).
The drive transmitted to the drive shaft 15a from the retard roller 1
3 The drive from the drive shaft 15a is also transmitted to the drive roller 8a of the discharge roller device 8 via an endless belt (not shown).

From the idler gear group 22 to the retard roller 1
The drive transmission to the motor 3 is performed via the torque limiter 20. When two or more documents are fed into the sheet separating device 10, the torque limiter 20 reverses the retard roller 13 and sends only the uppermost document to the transport roller device 14 on the downstream side. The lower document works to be sent back to the document tray 51.

Incidentally, as described above, the retard roller 13 is supported by the support bracket 24, and the opening of the bearing 69 of the support bracket 24 can be detachably connected to the connection shaft 25 (see FIG. 1) of the swing frame 26. Have been. Further, the retard roller 13 and the torque limiter 20 are connected to the shaft 1.
3a. Therefore, the replacement of the retard roller 13 and the replacement of the torque limiter 20 can be simplified. Of course, only the torque limiter 20 can be replaced.

The ADF 1 shown in FIG. 1 is, for example,
As shown in FIG. 5, it can be used in combination with an image reading apparatus 40 provided integrally with an image forming apparatus such as a copying machine or a facsimile machine. In the image reading device 40, the scanning device 43 includes a full-rate carriage 44 provided with a lamp 44a and one mirror m1, similarly to a device used in a generally known scanning device of a copying machine. A pair of opposing mirrors m2, m3
Are provided in combination with a half-rate carriage 45 for disposing.

Then, the read information of the document is transferred to the lens device 4.
The optical signal is transmitted to the CCD 49 via the optical signal converting unit 8, and the optical signal is converted into an electric signal and transmitted to the image information processing unit of the image forming apparatus. In the scanning device 43, two pulleys 46, 46 having a diameter of 2: 1 are used to drive the full rate carriage 44 and the half rate carriage 45.
A mechanism is provided in which the two carriages are moved in conjunction with each other via wires 47, 47a wound around a.

On the upper part of the frame 41, there are provided a platen 42 on which an original of a book is placed and corresponding to the operation as the FBS, and a platen 7 which is arranged at the lower part of the original conveying path corresponding to the ADF. . With respect to the platen 42, the platen cover 50 is opened and a document is set, and the platen cover 50 is closed, so that the platen cover 50 presses the image surface of the document on the upper surface of the platen 42 to scan the set document. Do.

For a document set on the platen 42, the full-rate carriage 44 reciprocates by the length of the document in accordance with detection information from a sensor (not shown), and the half-rate carriage 45 The image information is read while moving at half the speed of the carriage 44, and an image signal is output via the CCD 49.

When scanning a document on a sheet using the paper feed tray 51, the document is transported as an ADF through a document transport path 6 provided in a document transport unit, and a platen 7 is scanned.
An image reading operation is performed while the scanning device 43 is fixed to the portion.

Using the document feed path 6, the paper feed tray 51
When scanning the original set in the printer, the setting of the original in the paper feed tray 51 is detected by using a detection unit (not shown), and the control device is operated based on the detection signal. This is performed by inputting a command to perform scanning using the document transport unit.

The full-rate carriage 44 of the scanning device 43 is stopped immediately below the platen 7 in response to a signal of a document reading command set in the image forming apparatus, and the half-rate carriage 45 is moved to the left end of the scanning unit frame 41. The original is transported one by one from the paper feed tray 51 in the horizontal U-shaped transport path 6, and the image of the original is read by the platen 7. Therefore, the scanning unit frame 41
In the scanning device 43 disposed on the
The scanning device 43 is set in correspondence with 2, 7, and can perform a reading operation for an arbitrary document, and a facsimile device at a remote location can be used by using the transmission function of the facsimile device.
Or a communication device (including a personal computer, etc.)
The image information can be transmitted to the printer, and the image can be printed on recording paper by utilizing the function of the copying machine.

In this embodiment, the retard roller is used as the separating member. However, the separating member may be replaced with a member having the function of separating sheets one by one, for example, a separating pad, and also includes modifications. Of course. Further, although a compression spring is used as the pressing elastic member, a configuration using a tension spring may be used if the retard roller can elastically contact the separate roller.

[0047]

According to the first aspect of the present invention, the separation member can be easily exposed and detached simply by opening the upper frame and removing the upper surface guide member which forms a part of the sheet conveyance guide. The maintainability of the member can be improved. Therefore, the serviceman can easily replace the retard roller in the field.

According to the second aspect of the present invention, since the separation member is supported by the support bracket to form a unit and the pressing force is applied to the bracket, the influence on the separation member can be obtained without directly pressing the separation member. Is small. In addition, since the support bracket is detachably and rotatably attached to one end of the arm member, replacement of the separation member becomes easier.

According to the third aspect of the present invention, the arm member is provided with the elastic pressing member on the side opposite to the side supporting the separating member. Therefore, when the separating member is directly pressed by the elastic member as in the prior art. In comparison, a smaller elastic pressing member may be used, and the height of the pressing force adjusting mechanism can be suppressed. Thus, the radius of curvature of the curved sheet conveying path can be reduced, so that the height of the sheet feeding device itself can be suppressed and the size of the device can be reduced.

According to the fourth aspect of the present invention, since most of the separation mechanism can be accommodated in the intermediate frame, the drive transmission mechanism can be arranged in a compact configuration, and the height of the sheet feeding device can be suppressed.

According to the fifth aspect of the present invention, since the paper feeding member is a separate roller and the separating member is a retard roller, the separating performance is improved.

According to the sixth aspect of the present invention, even if a paper jam occurs, the jammed paper can be easily and immediately removed by opening the intermediate frame.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an ADF to which the configuration of the present invention can be applied.

FIG. 2 is a side sectional view when a retard roller is attached to and detached from an ADF.

FIG. 3 is a plan view showing a state where an upper surface guide member is removed from an intermediate frame.

FIG. 4 is a plan view of an upper surface guide member.

FIG. 5 is a side cross-sectional view of an image reading apparatus including an ADF.

FIG. 6 is an explanatory view of a conventional pressure adjusting means for a retard roller.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 automatic document feeder (ADF) 2 upper frame 3 intermediate frame 5 paper transport guide 8 discharge roller device 10 pickup roller 12 separate roller 13 retard roller 14 transport roller device 24 support bracket 26 arm member 30 pressing force adjusting means 32 elastic pressing member 51 paper feed tray 52 paper output tray

Claims (6)

[Claims] A feed path connected to a paper feed tray and a paper discharge tray and provided with a pair of paper transport guides; a paper feed member supported by an openable upper frame; A detachable separating member which partially protrudes toward the conveyance path side and is arranged to elastically contact the paper feeding member inside one of the paper conveyance guides of the guide; A sheet feeding device characterized in that the separation member can be replaced by removing a part of the transport guide. 2. The apparatus according to claim 1, wherein the separation member is integrally supported by a support bracket, and is detachably and rotatably attached to one end of an arm member that is swingably provided in the conveyance guide. The sheet feeding device according to claim 1, wherein 3. A paper feed tray which connects a paper feed tray and a paper discharge tray, includes a pair of paper transport guides, a curved transport path, a paper feed member supported by an openable and closable upper frame, and the one paper transport. A detachable separation member partially protruding from the conveyance path side inside the guide and disposed so as to elastically contact the paper feeding member, and an arm member is attached to the paper conveyance guide in a swingable manner. A sheet feeding device. 4. The support bracket, the arm member, the elastic pressing member, and the separating member are housed in an intermediate frame provided to be able to swing up and down, and the intermediate frame is further provided with a paper-conveying drive roller. The sheet feeding device according to claim 3, wherein 5. The paper feed member is a separate roller for transporting the paper to an image processing unit, and the separation member is a retard roller that rotates in a direction opposite to the paper transport direction and separates the paper one by one. The method according to claim 1, 2, 3, 4, or 5.
The paper feeding device according to any one of the above. 6. An inner surface of the upper frame forms a part of the other transport guide of the pair of transport guides. The frame further includes a pickup roller and a driven roller for transporting the paper. 2. The sheet feeding device according to claim 1, wherein a part of the conveyance path is opened, and the intermediate frame is swingable up and down.